Some bankers could soon learn that what their employer giveth, it can taketh away.

As a growing number of shareholders threaten to sue financial firms that doled out fat bonuses to bankers who created securities triggering the financial crisis, several of those firms, including PNC Financial Services, are setting up committees to examine past pay practices, sources told The Post.

Meanwhile, other financial firms are hiring lawyers and hunting for compensation consultants to help them review claims that past bonus payments were unreasonable in light of last year’s staggering losses.

PNC declined to comment, but sources tell The Post the bank’s board has formed a committee that includes two of its independent directors. In addition, Philadelphia-based law firm Harkins Cunningham is advising the committee and searching for a compensation consultant to help it review pay practices, sources said.

Sparking the concern at PNC and other firms is the threat of litigation by the $1.3 billion SEIU Master Trust, a consortium of Service Employees International Union pension funds.

Earlier this year, the trust hired law firm Grant & Eisenhofer, which issued letters to the boards of 29 companies including PNC, BlackRock, AIG, Goldman Sachs and Morgan Stanley.

The letters accuse the firms of paying a combined $5 billion of executive compensation on false presumptions. They also demand the firms launch investigations into the matter.

Sources said several of the target companies are hunkering down to do just that.

Compensation consultants told The Post they’re getting phone calls from firms that need help to review how best to respond to SEIU’s demands. Lawyers, too, are getting new business.

“It’s a common step by a responsible board to appoint a subgroup of the directors to be in charge of investigating whether the allegations made in the demand add up,” said one lawyer who said he knows of three firms that have established board committees in response to the letter.

Of course, skeptics charge all the hubbub is simply window-dressing to stave off litigation.